In this paper, a basic linearly polarised microstrip square patch antenna operating at 2.4 GHz is proposed. We have modified the basic microstrip square patch antenna with rectangular shape slits, V shape slits and truncated corners to achieve circular polarization. Basically we have designed five different antennas to meet the specification. The various antennas have been simulated, fabricated and the performance has been tested on network analyser (Agilent Technologies: N9912A, SNMY51464189, ROHDE & SCHWARZ: ZVL13, 9 KHz to 13.6GHz,). The simulated and tested performance shows close agreement with each other. The various structures used in this study are microstrip square patch radiator, microstrip square patch radiator with truncated corner, rectangular slits, truncated corner with rectangular slits and V shape slits. The experiment results show rectangular slits with truncated corners in the main square patch and rectangular slits in the main square patch provide better performance with respect to the antenna parameters. Designed antenna is compact and provides circular polarization at the required operating frequency of 2.4GHz with improved bandwidth and gain. The use of circularly polarized antennas presents an attractive solution to achieve this polarization match which allows for more flexibility in the angle between transmitting and receiving antennas. It gives the following advantages such as reduction in the effect of multipath reflections, decrease in transmission losses, enhancement of weather penetration and allowing any orientation to the communication system.